You can download your certificates in the Training Records section of you profile. If it will not open, you might need to turn off your browser's popup blocker.
Chrome
Open Chrome.
At the top right, click More. Settings.
Under "Privacy and security," click Site settings.
Click Pop-ups and redirects.
To Enable Pop-ups - Select Sites can send pop-ups and use redirects.
To Disable Pop-ups - Select Don't allow sites to send pop-ups or use redirects.
Safari
Open a Safari browser window.
Select the “Safari” menu, and then select “Preferences” from the drop down menu.
The preference pane will open and then select “Security” on the top row.
Uncheck the checkbox "Block pop-up windows".
Close the Preferences window.
Edge
Open Microsoft Edge.
Go to the three-dot menu icon in the top right corner.
Scroll down and select “Settings.”
In the left panel, choose “Privacy, search, and services.”
Under “Security,” click on “Cookies and site permissions.”
Toggle off the “Block pop-ups” option.
Firefox
Click Tools in Menu Bar. ...
Select Settings. ...
Click Privacy & Security located on the left side.
Select Block pop-up windows below the Permissions section. ...
Click OK.
Exit and relaunch the browser.